Add explicit checks for lyrics texts fetched from the tested sources.
- Introduced `LyricsPage` class to represent lyrics pages for integrated
tests.
- Configured expected lyrics for each of the URLs that are being
fetched.
- Consolidated integrated tests in a new `TestLyricsSources` class.
- Mocked Google Search API to return the lyrics page under test.
Since at least one Backend requires album` and `duration` arguments
(`LRCLib`), the caller (`LyricsPlugin.fetch_item_lyrics`) must always
provide them.
Since they need to provided, we need to enforce this by defining them as
positional arguments.
Why is this important? I found that integrated `LRCLib` tests have been
passing, but they called `LRCLib.fetch` with values for `artist` and
`title` fields only, while the actual functionality *always* provides
values for `album` and `duration` fields too.
When I adjusted the test to provide values for the missing fields,
I found that it failed. This makes sense: Lib `album` and `duration`
filters are strict on LRCLib, so I was not surprised the lyrics could
not be found.
Thus I adjusted `LRCLib` backend implementation to only filter by each
of these fields when their values are truthy.
Modified `search_pairs` function in `lyrics.py` to:
* Firstly strip each of `artist`, `artist_sort` and `title` fields
* Only generate alternatives if both `artist` and `title` are not empty
* Ensure that `artist_sort` is not empty and not equal to artist (ignoring
case) before appending it to the artists
Extended tests to cover the changes.
- Consolidated multiple test cases into parameterized tests for better
readability and maintainability.
- Simplified assertions by comparing lists of actual and expected
artists/titles.
- Added `unexpected_empty_artist` marker to handle cases which
unexpectedly return an empty artist. This seems to be happen when
`artist_sort` field is empty.
- Replaced unittest.mock with pytest fixtures for better test isolation and readability.
- Simplified test cases by using parameterized tests.
- Added `requests-mock` dependency to `pyproject.toml` and `poetry.lock`.
- Removed redundant helper functions and classes.
- Refactored Tekstowo backend to fetch lyrics directly from song pages.
- Added `encode` method to convert artist and title to their URL format,
where non-alphanumeric characters are replaced with underscores.
- Removed the now redundant search functionality and associated tests.
- Simplified `extract_lyrics` method to directly parse lyrics without
any checks.
External Python packages interfacing beets may want to use an in-memory
beets library instance for testing beets-related code.
The `TestHelper` class is very helpful for this purpose.
Previously `TestHelper` was located in the `test/` directory.
Now it is part of `beets` itself (`beets.test.helper.TestHelper`) and
can be easily imported.
